查询词典 parametrization

The process of converting the algebraic surface into the parametric surface is called parametrization , which has received much attention in recent years.

这种方法首先解决了基线扫描参数化方法中不能得到有理参数表达式的问题，给出了混合曲面的统一、低次的有理参数化。

If the surface isrepresented by an implicit algebraic equation,the mapping can be constructed bythe theory of parametrization of algebraic surfaces;If the surface is represented byan parametric equation,the parameter values on the parameter plane can be solvedby numerical method or Grobner Basis method.

若曲面由代数隐式方程给出，可通过代数曲面参数化理论构造映射；若曲面由参数方程给出，可通过数值方法或Grobner基方法求解参数型值点。

Net compile environment to established the double circular arc gear parametrization modeling system.

Net编译环境建立了双圆弧齿轮参数化建模系统。

For genus zero closed surfaces,the parameter domain is sphere,so the cutting of the surface meshes in the parametrization process is avoided.

对于零亏格封闭网格曲面，以球面为参数域的参数化方法可以有效避免对网格的切割，是近年来的研究热点。

Based on the summarizing of the exiting algorithms of the texture mapping and antialiasing, this paper goes deeply into the basic theory and processing of texture mapping. The texture compress algorithm which can satisfy the need of the memory and time is given for the stochastic sampling in the inverse texture mapping; the geometry transformation in the texture mapping are discussed and the concepts of the unitary parametrization and the patch parametrization is proposed, some kinds of the unitary parametrization methods of parametric surfaces and the geometry transformation in the patch parametrization are also presented; in order to solve the aliasing in the parametrization of intermediate surface-sphere in two-part texture mapping, an area-preserving transformation is presented also; to improve the quality of the graph the aliasing in the texture mapping is analyzed from the aspect of signal process, and the modified summed-area tables algorithms is proposed; the distortion of the scanline conversion algorithms under perspective transformation is analyzed and the proper interpolation algorithm is presented so the aliasing problem of the polyhedral object after the unitary parametrization is efficiently solved.

本文在总结现有的纹理映射和反走样算法的基础上，深入研究了纹理映射的基本原理与过程，根据反向纹理映射对纹理随机采样的特殊要求，提出了一种可满足存储空间和寻址时间的纹理压缩存储算法；通过对纹理映射中几何变换理论的进一步深入探讨，提出了整体参数化和面片参数化的概念，并给出了参数化曲面的各种整体参数化方法和面片参数化的几何变换形式；针对现有的两步映射算法所存在的中间曲面—球面的参数化问题，提出一种等积映射方法，较好地实现了由非参数化面片拼接而成的多面体表面的纹理映射；从信号采样的角度深入分析了纹理映射中走样产生的原因，提出了改进的区域求和表算法，使图形生成的效果有所提高；还分析了一般的扫描线算法在透视变换中所存在的问题，提出了一种正确的插值算法，从而解决了整体参数化后多面体表面纹理映射的几何变形问题。

On the basis of a great deal of information, several general problem on land sarface process parametrization for a global circulation model and its history of development are described. The Bucket model, EARTH, ISBA and SiSPAT models are respectively expounded, and the situation of studies on land surface process parametrization is summarized. China is a participating country of the international geosphere-biosphere program and the study on circulation of global energy and moisture, and has put forward some valuable soil-vegetation-atmosphere models for land surface process parametrization. which results in effective studies on vegetation indexes.

在大量资料基础上，叙述了大气环流模式陆面过程参数化方案的一般问题及其发展历程，分别阐述了水桶模式、EARTH模式、ISBA模式和SiSPAT模式；总结了在陆面过程参数化方面的研究状况，我国参与了国际地圈生物圈计划和全球能量与水分循环的研究，特别是在陆面过程的参数化研究方面，提出了一些有价值的土壤—植物—大气模式，对植被指数进行了有成效的研究。

Then discusses 3D parametric representation, which includes 3D geometry parametrization and relative position relationship parametrization.

文中首先分析了约束与设计意图的关系及其对产品构成的影响。

Part five discusses 3D model parametric representation, which includes 3D geometry parametrization and relative position relationship parametrization. In the former, the sweeping rules are further formalized, the concept of design parameters and modeling parameters is introduced. In the later, constraint transformation matrices of the position relationships between features are deduced, and the lost of model freedom resulted from the correspending constraint is analysed.

在特征几何参数化中，进一步规范化了特征几何的扫描生成规则，引入了设计参数和造型参数的概念，分析了造型参数向设计参数适时转化的必要性；在相对定位约束参数化中，推导了特征间一般位置约束关系的约束变换矩阵，拓宽了约束表示范围，并对约束的自由度亏损情况进行了分析。

This kind of parametrization, named as spherical parametrization,becomes the popular topic.

这类方法统称为球面参数化方法。

Based on the review of progress in parametric uncertainty nonlinear system control theory, it is noticed that design methods based on feedback linearization are the main parts and the author proposes a robust controller design method for a nonlinear parametrization uncertain system satisfying feedback linearization and triangularity conditions,and a robust output tracking controller for a nonlinear parametrization uncertain system based on the identification of uncertain parameters.

在对该领域研究进展分析的基础上，针对满足三角形条件和反馈线性化条件的非线性参数化不确定系统提出了一种鲁棒控制器设计方法，并针对非线性参数化不确定系统提出了基于参数识别的鲁棒输出跟踪器的设计方法。后者是本文为飞机防滑刹车系统设计输出跟踪器的理论基础，同时也是本文的创新点之一。在对结合力产生本质讨论的基础上，分析了滑水现象产生的原因和预防措施。

By the time of its fall, most of the prisoners were writers who had written against the corruptions of the government.

到它被攻陷的时候，里面多数的犯人是写了反对政府贪污文章的作家。

The most obvious variation to ovum morphological character was that the color was changed from light green to sepiaceous in embryonic development, and all the ovums were almost hatched after 96h.

在胚胎发育过程中卵的形态特征最明显的变化是颜色从淡绿到深褐色，卵在发育96h后卵基本全部孵化。